Privacy: "You Have Nothing to Fear if You've Done Nothing Wrong"
Strange, most of these people don't want me walking into their home and watching me them make love, or watch their kid 24 hours a day, or peep into their showers, or steal their secret family recipe. Why? Do they have something to hide?
In a sense, yes. They have legitimate activity that they want to do in the seclusion of their own homes.
Now, mind you, I know privacy is often used as a shield for wifebeating... but that's patriarchal norms that we should alter, not the right of privacy per se.
The very point of privacy restrictions is that any polity, particularly the state, will have a chilling effect upon very legitimate activity; that allowing the state to monitor activity in an unlimited manner allows corrupt people to watch; that trusting the state, especially if the state can be changed and taken over by less-than-nice people, is a fantastic way to get tyrany; and the only way to limit this is to risk some degree of loss of police power.
It is also true that privacy rights can be over-extended to apply to non-privacy issues. Privacy implies private spaces: one's mind, one's house, one's doctor's or lawyer's office. Abortion, for example, is only arguably within such boundaries.